------------[ cut here ]------------ kernel BUG at fs/buffer.c:2666! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 6085 Comm: kmmpd-loop0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : submit_bh_wbc+0x3e0/0x44c fs/buffer.c:2666 lr : submit_bh_wbc+0x3e0/0x44c fs/buffer.c:2666 sp : ffff800021a07bb0 x29: ffff800021a07bc0 x28: ffff0000fcf01008 x27: dfff800000000000 x26: 1fffe0001a2664cf x25: 0000000000000000 x24: 1fffe0001c13df79 x23: ffff700004340f88 x22: ffff0000d1330000 x21: 0000000000003801 x20: ffff0000e09efbc8 x19: 0000000000000005 x18: ffff800011b9bf60 x17: 1fffe00033ea637e x16: ffff8000082d7db8 x15: ffff80001521d000 x14: 0000000000000001 x13: 1fffe0001c13df85 x12: 0000000000ff0100 x11: ff00800008a94fc0 x10: 0000000000000000 x9 : ffff800008a94fc0 x8 : ffff0000cb2c1bc0 x7 : ffff800008dcdfbc x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff800008dcdb38 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: submit_bh_wbc+0x3e0/0x44c fs/buffer.c:2666 submit_bh+0x2c/0x3c fs/buffer.c:2707 write_mmp_block_thawed+0x320/0x4c4 fs/ext4/mmp.c:51 write_mmp_block+0x1e4/0x5f0 fs/ext4/mmp.c:67 kmmpd+0x2c4/0x938 fs/ext4/mmp.c:178 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 Code: 17ffffad 97e85999 d4210000 97e85997 (d4210000) ---[ end trace 0000000000000000 ]---